Quantitative Evaluation of Slurry Flow Behavior using Digital Image Processing

Effect of Lapping/Polishing Process Parameters on Slurry Flow

Abstract

Lapping/Polishing process is generally used in fabricating high-accuracy wafers. In this process, slurry mixed free abrasive grains and water or dispersion oil is used. It is well known that the process characteristics are affected by actual slurry flow in the contact surface between the wafer and platen/polishing pad. Therefore, stabilization of slurry flow is required to improve the process characteristics. This paper presents the quantitative evaluation results of slurry flow behavior by changing of the processing parameters; the grain size, materials and rotational speed of the platen and wafer. Furthermore, digital image correlation (DIC) method was used for quantification. As a result, the following points were observed. (1) Slurry flow is easy to be affected by the relative motion between the platen and wafer owing to increase of the grain size. (2) Slurry flow is depended on the hardness and the rotational speed.